Fade is a really rubbish version of Canabalt that somehow manages to still be fun and chucks in some RPG elements into the mix.
Fade is one of those games that you sort of recognise is a bit rubbish, but you just can't help but play it regardless. It's basic mechanic is compelling - it's the reason why Canabalt is so awesome - but the RPG element, which allows you to increase your running speed, add double jumps, etc legitimately kept me coming back for more. Right about the time when I felt like I should be getting bored, I was being dragged along with the carrot of extra acceleration or the ability to climb up walls.
So yeah, Fade is a lot of fun despite itself!